I had 28 apps on my 5s when I last backed it up, and reinstalled 20 of them when setting up my new 6s with the backup. The leftover apps are mostly stuff I didn't use much, but some of them (such as Dropbox) had user account info and I'm wondering if that info is still floating around. Almost all of the reinstalled apps that required an account were already logged in when I used them for the first time on the 6s. So I don't want my logon info for Dropbox and others to be out there. Is there a way to make sure?